Pulse delay measurements in single-mode fibers using sum-frequency mixing as a picosecond shutter

We describe a novel technique for measuring pulse delay in single-mode fibers. Relative time delay changes between different wavelengths are used to determine dispersion on both sides of the zero total dispersion wavelength. In this technique the sum-frequency mixing is used as a picosecond shutter. The measurement accuracy and the input power limitation to avoid the influence of stimulated Raman scattering for the measurement are described. Furthermore, dispersion characteristics on three single-mode fibers are measured, and it is pointed out from the experimental results that a larger refractive index difference and a shorter cutoff wavelength shift the zero total dispersion point toward the longer wavelength.